System of control.



R. E. HELLMUND.

SYSTEM OF CONTROL.

APPLICATION FILED MAR. I. 1917.

Patented Mar. 4,1919.

Ground Maforing Regenera fing INVENTOR Rudolf 1;. He llmund Fig. 1

WITNESSES Kw $22M;

BY fl ATTORNEY UNITED STATES PATENT OFFICE.

BUDOLF E. HELLMUND, OF SWISSVALE, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

V SYSTEM OF CONTROL.

Specification of Letters Patent.

Patented Mar. 4, 1919.

. To all whom it may concern:

Be it known that I, RUDoLr E. HELLMUND, a citizen of the United States, and a resident of Swissvale, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Systemsof Control, of which the following is a specification.

Myinvention relates to systems of control and especially to that type of system wherein auxiliary-machine .armatures are employed in conjunction with the main machines to efiect both accelerating and regen erative operation thereof.

The object of my invention isto provide a system of the above-indicated character which shall be relatively simple and inexpensive-in construction and effective and rehable in operatlon to accomplish accelerating'or regenerative operation of the main machine or machines Without the use of resistors.

More specifically stated, it is the object of my invention to provide, in conjunction with one or more-mam machines, a plurality of auxiliary mechanically-connected armatures, one of which'is connected in series relation with, and the other of which is connected in parallel relation to, the main machine or machines, each of the auxiliary armatures being provided with a subdivided field winding the parts of which are respectively energized by the main-circuit current and by current from the corresponding; auxiliary armature.

My invention may best be understood by reference to the accompanying drawing, wherein Figure 1 isa diagrammatic view of the essential parts of a system of control embodying my invention; Fig. 2 is a sequence chart of well-known form for indicating the preferred order of operation of the switches illustrated in Fig. 1 during both accelerating and regenerative operation; Fig. 3 and Fig. 4 are simplified diagrammatic views illustrating the circuit connections under n1otoring or accelerating conditions and under regenerative conditions, respectively; and

Fig. 5 is a diagrammatic view of a modification of a portion of the circuits shown in Fig. l. 1

Referring to the drawing, the system shown comprises suitable supply-circult conductors respectively marked Trolley and Ground; a main dynamo-electric machine having an armature A and a field winding 1 of the series-type, a conventionally-illustrated reverslng switch RS, of any familiar form, for reversing the electrical relations of the main armature and field winding; a plurality of suitable switching devices LS and 1 to 15, inclusive; and an auxiliary motor-generator or booster set, comprising a motor or driving armature 20 that. is mechanically connected to a driven or generator armature 21 by a shaft 22, or otherwise.

The auxiliary motor armature 20 is provided with a subdivided field Winding 23 of the series type, while the auxiliary generator armature 21 is provided with a similar type of subdivided field winding 24. To impose a certain mechanical load uponthe seriesexcited motor-generator set and thus preelude any possibility of unduly high speed thereof, irrespective of the electrical load conditions, alsuitable blower 25,.for example,

for furnishing jventilating air to the main machine or machines,may be utilized.

The swltches 1, 2 and 3 are associated with different tap-points of the auxiliary motorfield winding 23 to connect it to the main machine, and switches 4, 5 and 6 perform a similar function with respect tothe auxiliary-generator field winding 24. Switches 7, 8, 9 and collectively act in the capacity of a reversing switch, switches 7 and 9 being employed for effecting the traversal of ourwinding 24; in the one direction durin acceleratin operation of the main mac inc, while switches 8 and 10, when closed, serve to produce a reversal'of such current, during the regenerative period. Switches 13, 14 and are associated with various selected points of the main field winding F for varying the active-circuit value thereof.

rent through the auxiliary-generator field Inasmuchas the particular system of auxiliary control that isemployed in connection with the main circults just described is immaterial to my present invention, it is not deemed necessary to illustrate or set forth any such system. The operation of the circuits shown will be 'eXplained'in connection with the sequence" chart of Fig. 2 and. such description, taken in conjunction with the simplified motoring and regenerating diagrams of Fig. 3 and Fig.4, is considered as sufiicient to fully set forth my present invention.

Assuming that it is desired to effect motoring or accelerating operation of the main machine, the master'controller, or its equivalent (not shown) is moved to its first operative position to efl'ect the closure of switches erator armature 21, switch 7, conductor 31,

the entire auxiliary field winding 24, conductors 32 and 33, switch 9 and conductor 34 to the negative conductor Ground.

The motor-generator or booster 'set is thus started into operation to produce a relatively low voltage for application to the terminals of'the main machine.

Upon the closure of the switches 3, 5, 12 and 15 in position b (Fig. 2), to thereby connect the main machine in circuit, the auxiliary generator armature 21 supplies the major portion of thenecessary accelerating current, while the supply circuit furnishes the remainder. Consequently, at

this time, as shown in a simplified manner in Fig. 3, a new circuit is completed from an intermediate point of the auxiliary motor field winding 23 through switch 3, conductor 37, main armature A, certain contact members (not shown) of the reversing switch RS,.the entire main field winding F, switch 15, certain other contact members of the reversing switch RS, conductor 38, switch 12, conductor 39, switch 5 to an intermediate point of the auxiliary generator field winding 24 and thence, through the lower portion thereof, to the negative conductor Ground, as previously traced.

As indicated by the various arrows in Fig. 3, the inclusion of the main machine in circuit effects a reversal of the initial currents traversing the lower portion of the auxiliary field windings'23 and the upper portion of the field winding 24, whilethe other parts of the field windings are correspondlngly strengthened by the traversal therethrough of additional current in the same direction, the relative magnitude of the various field-winding parts being predetermined by the initially selected switches, in this case, 3 and 5, respectively. It willbe understood that, by suitably proportioning the various parts of the 111118! trated machines, the resultant eifect of the connection of the main machine in circuit and the above-described changes in the aux iliary field-winding conditions may be such that the relative voltage distribution between the generator armature 21 and the auxiliary-motor armature 20 will remain substantially the same as before the inclusion of the main machine in circuit or may be varied to impress any desired value of voltage upon the main machine.

The voltage of the auxiliary armature 21 may be subsequently increased by a virtual upward shifting of the point of intercon nection of the main-machine circuit and the auxiliaryfield winding 24, thus increasing the positive or aiding excitation of the lower portion of the field winding and correspondingly decreasing the negative or opposing excitation of the upper part of the field winding. A corresponding upward movement of the point of connection of the main machine to the auxiliary motor field winding 23 will also serve to effect a gradual increase of thegpltage impressed upon the main mach me by iii'creuising the lower or negatively-acting portion of the field winding and decreasing the upper or positively-acting part, in this way, gradually reducing the voltage of the auxiliary motor armature 20 and correspondingly increasing the electromotive force impressed upon the main machine.

Such variation of the relative magnitude of the various auxiliary field-winding parts may be readily accomplished by, the proper manipulation of the switches 1 to 6. inclusive, as indicated by the sequence chart, Fig. 2. In position a of the master controller (not shown), for example, switch 2 1 may be closed, whereupon switch 3 is opened, while, in position d, switch 4 is closed and switch 5 isthen opened. In the next position e, switch 1 is closed just prior to the opening of switch 2, and'thus, the final connections of the main machine and the'auxiliary field windings 23 and 24 include the uppermost switches 1 and 4, respectively.

To produce further acceleration of the main machine, switch 14 may be closed and switch 15 then opened, whereby a predetermined portion of the main field winding F is excluded from circuit to effect the desired increase of main-machine speed, in accordance with familiar principles.

Assuming that conditions are suitable for regenerative operation, the main-circuit reversing switch BS is first actuated to its other position to reverse the electrical relations of the main armature and field winding for a well-known purpose, and switches 8 and 10 are also closed to eflect a reversal of the interconnections between the auxiliary generating armature 21 and its field winding 24.

.Switches LS and 2, 4, 11 and 13 may then 'be closed, whereby a relatively small negatablished from one terminal of the auxiliary armature through the switch 8, conductor 32, corresponding auxiliary field winding 24 in the reversed direction, conductor 31,- switch 10, conductor 38, main re:

versing switch BS in its reversed position,-

switch 13, a relatively small portion of the main field winding F, reversing switch RS, the main armature A, conductor 37, inter mediate switch 2, a predetermined lower portion of the auxiliary motor field winding 23 and conductor to the other terminal of the auxiliary-generator armature 21.

Such initial impression of a negative voltage upon the reversed main machine, now acting as a series generator, causes a rapid building up, of the regenerated voltage in the proper direction, as will be understood. As soon as the main-machine voltage and current have increased to suitable operating values, the currents traversing the upper portion of the auxiliary-generator field wint ing 24 and the lower portion of the auxiliary-motor field winding 23 are reversed, with respect to the corresponding currents during acceleration, as clearly shown by the arrows in the simplified diagram of Fig. 4:, by reason of the connection of the main machine to the selected intermediate points of the auxiliary field windings.

Thus, both portions of the auxiliary-generator field winding 24 act cumulatively and induce a relatively strong positive counter electromotivxforce in the auxiliary armature 21. At the same time, the current relations in the two portions of the auxiliarymotor field winding 23 are difl'erential 0r opposed, the one to the other, to produce a temporary decrease of the voltage of the corresponding auxiliary armature 20.

Regulation of the regenerative system to compensate for the gradual decrease in main-machine speed preferably comprises the gradual increase of the active circuit value of the main field winding F by the closure of switch 1-1 and the subsequent opening of switch 13 and again by theclosure of switch 15 just prior to the opening of switch 14, as indicated by positions I) and 0' of the sequence chart, Fig. 2.

In position d, switch 5 is closed and switch 4 then opened to vary the relative magnitude of the parts of the auxiliary-gem erator field winding 24 that are traversed by the main regenerative current and the mature 20 and correspondingly decreasing the regenerated voltage of the main arma ture A; In the final position 7, switch 6 is closed and switch 5 is then opened to further continue the desired distribution of voltages between the various machines. f

Thus, by suitable proportioning of parts, the regenerated voltage of the main armature may be gradually reduced to a "relatively low value, while the voltage of the auxiliary armature 20 correspondingly increases to absorb the remaining voltage necessary to insure regenerative operation. I have thus provided a relatively simple set of circuits for effecting both accelerating and regenerative operation of a inain'machine without the use of either main or auxiliary-circuit resistors, whereby a simple, in- -76 expensive and economical control system is obtained.

I desire it to be understood that the expression connected in parallel relation to said main armature, as used in the claims, reference being had to the auxiliarygenerator armature 21, is intended to cover other equivalent circuit arrangements, such as the connection of the generator armature substantially across the supply circuit. Furthermore, I have intended to cover equivalent auxiliary field-winding connections, such as the use of a circuit comprising inductive and non-inductive resistors 26 and 2 7, respectively, in parallel relation to an auxiliary field winding, and connection of the main-machine circuit to the inductive resistors, the non-inductive resistors being varied to effect the desired regulation, as in dicated in Fig. 5.

I donot wlsh to be restricted to the specific circuit connections or arrangement of parts herein set forth, as various modifications thereof may be effected without departing from the spirit and scope of my in- 100 vention. I desire, therefore, that only such limitations shall be imposed as are indicated in the appended claims.

I claim as my invention:

- 1. In a control system, the combination 106 with a main dynamo-electric machine having an armature and a field winding, of a plurality of auxiliary dynamo-electric machine arniatures respectively connected in series relation with, and in parallel relation to, said main armature and each provided with a field winding that is energized in ac cordance with different currents, said field windings being subdivided and the parts of each field winding, under predetermined respectively energized, under predetermined conditions, by difi'erent circuits.

3. In a control system, the combination with a main dynamo-electric machine havchinearmatures respectlvely. connected in series relation with, and in parallel relation to, said main-armature and each provided with a field wir'iding partially energized by main-circuit current and partially energized by the currenttraversing the corresponding auxiliary armature.

, 5. In a. control system, the combination with a main dynamo-electric machine having an armature and a field winding, ofa plurality of auxiliary dynamo-electri machine armatures respectively connected in series relation with, and in parallel relation to, said main armature and'each provided with a:

plural-part field winding, means for initially energizing a predetemiinedpart of each plural-part fieldwinding in a certain-direction, and means for including the main machine in circuit to thereby efiect'a reversal of the energization of saidpredetermined parts. a,

6. In a control system, the, com in i n with a main dynamo-electric machine having an armature and a field winding, of a. plurality of auxiliary dynamo-electrictmachine armatures respectivelyv connected in series relation with, and in parallel relation to, said main armature and 'each provided with a plural-part field-winding, meansfor initially energizing a predetermined part of each plural-part field winding from one of said auxihary armatures 1n a certain direction, means for including the mam machine in circuit to thereby effect a reversal of current through said iredetermined parts, and means for varying t e relative magnitudes of said parts. g

7. In a control system, the combination with amain dynamo-electric machine having an armature and a field winding, of a plurality' of auxiliary dynamo-electric machine armatures respectively connectedin series relation with, and in parallel relation to, said main armature and each provided with a plural-part field winding means for initially energizing a predetermined part of each plural-part field winding in a certain direc tion means for including the main machine in clrcuit to thereby efi'ect a reversal of the energization of said predetermined parts, and means'for varying the relative magnitudes of said parts and for varying the active value of the main field winding to regulate the main-machine action.-

8. In a control system, the combination With a main dynamo-electric machine having an armature and a field winding, of a plurality of auxiliary dynamo-electric machine armatures respectively connected in series relation with, and in parallel relation to, said main armature and each provided with a plural-part field winding, means for initially energizing a predetermined part of each plural-part fie d winding from one of 'said auxiliaryarmatures in a certain direction, means for including the main machine in circuit to thereby effect a reversal of current through said predetermined parts, and means for varying the relative magnitudes of said parts and for decreasing the active value of the main field winding to effect acceleration of the main machine. I

9. In a system of control, the combination with a main dynamo-electric machine having an armature and a field winding, of a plurality of auxiliary dynamo-electric machine armatures respectively connected in series relation with, and in parallel relation to, said main armature and each provided with a plural-part field winding, means for initially energizing a predetermined partof each plural-part field winding from the parallelrelated auxiliary armature in a certain direction, means for including the main machine in circuit to thereby efi'ect a reversal of current through said predetermined .parts and c an increase of current through the remaining field-winding parts, and means for increasmined parts and for decreasing the active value of the main field Winding to elfect ac-.

celeration of the main machine.

10. In a control system, the combination with a main dynamo-electric machine having an armature and a field Winding, of a plurahty of auxiliary dynamo-electric machine armatures respectively connected in series a ing, the magnitude of said initially predeterrelation with, and in parallel relation to, said I main armature and each provided with a plural-part field winding, and means for reversing the field winding'of the main machine and of the parallel-related auxiliary machine preliminary to regenerative operation, whereby the main-machine voltage is rapidly built up tothereupon send currents through a part of the field winding of the parallel-related auxiliary machine in an aiding direction and through a part of the field winding of the series-related auxiliary machine in an opposing direction.

11. In a control system, the combination with a main dynamo-electric machine having an armature and a field winding, of a plurality I of auxiliary dynamo-electric machine armatures respectively connected in series relation with, and in parallel relation to, said built up to thereupon send currents through a part of the field winding of the parallelrelated auxiliary machine in an aiding direction and through a part of the field winding of the series-related auxiliary machine in an opposing direction, and means for vary ing the magnitude of said field winding,-

parts.

12. In a control system, the combination with a main dynamo-electric machine having an armature and afield Winding, of a plurality of auxiliary dynamo-electric machine armatures respectively connected in series relation with, and in parallel relation to, said main armature and each provided with a plural-part field winding, means for reversin the field windings of the main machine an of the parallel-related auxiliary machine preliminary to regenerative operation, whereby the main-machine voltage is rapidly built up to thereupon send currents throu h a part of the field winding of the paral el-related auxiliary'machine in an aiding direction and through a part of the fieldwinding of the series-related auxiliary machine in an oppoing direction, and means for varying the magnitude of said field winding parts and of the main field winding to compensate for a decrease of the main-machine speed.

In testimony whereof, I have hereunto subscribed my name this 23rd day of Feb. 1917.

RUDOLF E. HELLMUN D. 

